1. Field of the Invention
This invention relates in general to magnetic recording and playback heads and, more particularly, to thin film magnetic recording and playback heads.
2. Description of Related Art
In the continuing drive for increased storage density in magnetic media storage devices, thin film magnetic heads have been developed. As opposed to earlier types of magnetic heads, the fabrication of which involves significant piecework and manual handling of individual parts, thin film magnetic heads take advantage of semiconductor fabrication processes to form a large number of heads simultaneously on a common substrate or wafer.
One such head which is formed by a, semiconductor thin film process is disclosed in the article, "A New Thin Film Head Generation IC Head" by J. P. Lazzari et al., IEEE Transactions on Magnetics, Vol. 25, No. 5, September 1989. A cross-sectional view of the Lazzari head is illustrated in FIG. 1 as head 10. Head 10 is fabricated within a recess 15 in a silicon substrate 20. A gap 25 is shown in the uppermost portion of a magnetic layer or yoke 30 situated within recess 15. Head 10 is shown positioned adjacent magnetic recording media 35. A magnetic coil 40 is wound around magnetic yoke 30. A plurality of sliders with respective heads 10 thereon are fabricated from a common silicon wafer substrate using semiconductor thin film processes. The sliders are then diced up into individual slider assemblies.
The gap width, L.sub.G, is defined to be the distance between the magnetic pole pieces which form the gap of a thin film head. The gap length of a particular head is generally related to the track width of the magnetic media on which the head records and plays back. In other words, the narrower the gap length of the head, the narrower the track width of the media becomes.
In recent times, the trend has been toward magnetic media exhibiting smaller and smaller track widths. This trend has been necessary in order to increase the storage density of data on magnetic media. Each magnetic medium of a particular track density has a corresponding magnetic head with a particular gap width. Unfortunately, a thin film head made for one track width tends not be compatible with media of another track width. This limitation has generally meant that a recording/playback device using a particular thin film head can only use media having a track width corresponding to that head.